Cleveland Clinic reexamines syphilis testing strategies after rise in cases

The rate of syphilis cases has significantly increased in recent years, leading the Cleveland Clinic Ob/Gyn & Women’s Health Institute to reexamine testing strategies.

The Centers for Disease Control and Prevention has reported a 171.9% increase in the syphilis infection rate in female patients aged 15 to 44 years, which has caused congenital syphilis cases to rise 291.1%. This increases the risks of low birth weight, hydrops fetalis, cardiac and neurological defects, stillbirth, and preterm birth in infants.

Cleveland Clinic is located in Northeast Ohio, where the number of syphilis infection cases per 100,000 people has risen from 26.4 in 2014 to 41.7. From 2016 to 2021, the rate of congenital syphilis rose by 82%.

Noting the alarming trend in rising rates of syphilis cases, Cleveland Clinic and the Center for Pediatric Infectious diseases conducted a retrospective study of women who received perinatal care between 2014 and 2021 at facilities within the health system.

In traditional screening for syphilis, a nontreponemal test takes place first, followed by a confirmatory treponemal test when positive. In an alternative reverse-screening method, a treponemal test occurs first, followed by a nontreponemal test when positive. Patients then receive a second treponemal test if the results are differing.

Further testing is needed to determine if a test result was true positive (TP) or false positive (FP), with FP results being more common than TP results in many populations. Cleveland Clinic has been using the alternative reverse-screening method since 2014.

There were 75,056 patients in the cohort from June 2014 through February 2021, along with 77,410 infants delivered. At first, screening was recommended for women at the first prenatal visit, with an additional visit at the early third trimester and delivery for high-risk women.

Early universal screening in the early third trimester was recommended from July 2019 onward. This strategy was implemented to address the rising rates of congenital syphilis.

There were 221 initial syphilis screens recorded, with an FP rate of 243.8 cases per 100,000 pregnancies and a TP rate of 50.6 cases per 100,000. The traditional algorithm was used for 46 screens, 38 of which were FP and 8 TP. The reverse algorithm was used for 175 cases, 145 of which were FP and 30 TP.

A past syphilis diagnosis had been given to 55% of women with a TP result, while 45% had a new diagnosis. In TP screens, women were more often Black, used marijuana, and had non-syphilis sexually transmitted infections.

Data on potential harm from syphilis screening during pregnancy is lacking. This includes time and expense associated with screening, FP results which lead to stress, incorrect labeling, and further diagnostic workup.

Further evaluations and treatments because of syphilis concerns occurred in 2 women with FP results and 1 infant in the study. In 2 high-risk patients, rescreen at delivery did not occur, leading to diagnosis after hospital discharged. Also, congenital syphilis developed in 1 infant.

Cleveland Clinic has provided updated syphilis screening guidelines to address inadequate testing and treatment. In these guidelines, they recommend screening all patients as early as the first trimester during the first prenatal care visit, and at 28 weeks’ gestation. Patients at risk of developing syphilis during pregnancy should also receive serologic testing at delivery.

Testing should also be conducted in patients with a fetal death after 20 weeks’ gestation, and individuals who have not had postnatal care should be screened at delivery. Patients with a history of syphilis should receive repeat rest at 28 weeks and delivery, and those at high risk of reinfection should receive monthly testing.

Reference

Rising syphilis rates prompt study of screening, diagnosis and treatment of pregnant patients. Cleveland Clinic. Accessed February 3, 2023.https://consultqd.clevelandclinic.org/rising-syphilis-rates-prompt-study-of-screening-diagnosis-and-treatment-of-pregnant-patients/